iPhone users have complained after incurring charges for internet browsing abroad by their network even when that function had been switched off.

One member of the MoneySavingExpert.com team received fees last month while overseas despite turning the 'data roaming' function off before leaving the UK and only using local WiFi to surf the web and download emails.

Others have complained on internet forums of being hit with similar charges despite turning data roaming off before leaving the UK (see the Cheap iPhone guide).

Using the internet overseas can cost up to 8 per megabyte (MB) on an iPhone, which can be used up in just one browsing session, meaning you could pay far more in that time than a month's browsing on a home computer.

Data roaming is the term to describe the receiving of internet and email data to your handset while abroad. Your mobile operator should not charge for WiFi as you are connecting via a different source.

O2, the largest UK iPhone seller, admits some of its customers received erroneous data roaming charges last summer after users received a picture message.

However, it insists the problem was solved in September by a software update and says there is no systematic problem with the iPhone, adding it has not received any official, related complaints.

Erroneous charges

The MSE reporter hit with charges received two sets of fees in March that totalled 10.55 immediately after switching his phone from airplane mode to normal mode.

He insists the data roaming function was never switched on during his holiday, while he has the necessary software O2 says should have prevented the charge and has not downloaded any unauthorised software.

Other O2 customers have made similar complaints. One said on an internet forum in March: "I was recently charged 30 for data roaming that I thought I had studiously avoided by switching data roaming off and only using a WiFi signal when I could get it."

Another forum poster said last month: "I am absolutely obsessive about ensuring my data roaming is switched off on my iPhone before I leave the country.

"But I just got a bill today with 100 of data charges - mostly showing as one day when in Spain and some charges from when I was in New York too. I know 100% for sure that I had data switched off."

Immediate refunds

O2 customer services agreed to refund the MSE reporter immediately after the problem was reported. One of the forum posters also got a swift refund but the other did not, according to their posts.

Daniel Lawrence, MoneySavingExpert.com consumer products analyst, says: "These stories highlight the importance of keeping tabs on your mobile data use at all times, and shutting your data connection off completely when you go overseas.

"It's possible to find free WiFi access in most locations so, if possible, use that instead and you shouldn't pay a penny."

iPhone manufacturer Apple failed to answer any questions from MSE.

What does data roaming cost on an iPhone?

The four networks that sell the handset charge the following per MB:

Update, 23 July: some data charges have changed since this story was first published.

  • O2. 3 in the EU, 6 elsewhere

  • Orange. 4 in the EU, up to 8 elsewhere

  • Tesco Mobile. 4 in the EU, 8 elsewhere

  • Vodafone. up to 4.99 per day for first 25MB in Europe, then 4.99 for every other 25MBs. Elsewhere, up to 14.99 per day for first 25MBs, then 14.99 for every other 25MBs

Loading the MSE homepage alone uses roughly 0.3MB when we tested it on an iPhone.

Under EU rules, within Europe, you can opt in to a spending cap of 50 (about 43). When you reach that ceiling, your data use will automatically be stopped. From July, the cap will apply to all users in the EU, not just those who opt in.

You can sometimes buy a bundle from your operator to reduce costs.

How to avoid data roaming charges

You should take three steps before you leave the UK, though if you have downloaded unauthorised software or there are problems with the iPhone you may still be charged.

  • Step 1. Ensure your software is up-to-date. When you plug your phone into iTunes you will be alerted to any new software updates. Then follow the on-screen prompts.

  • Step 2. Switch off the data roaming function on your handset BEFORE you leave the UK and keep it off. While it is on, some apps trigger data downloading even when you're not browsing the web.

    When you buy an iPhone, data roaming should be 'off' by default. You can check by going to settings->general->network, where it's the third option down.

  • Step 3. Ensure your email is set to retrieve messages manually to stop it happening by surprise in case you need to turn data roaming on.

Then, while overseas, only connect using WiFi. If you've no choice but to use data roaming, remember to switch it off as soon as possible.

Have you been hit with iPhone data roaming charges after following ALL the steps above? If so, please report in the discussion below, or if you'd like us to investigate, email news@moneysavingexpert.com and include a brief outline of what happened and a daytime telephone number.

Further reading/Key links

Cut overseas costs: Mobile roaming
Slash mobile costs: Cheap Mobiles
Sell old mobiles: Sell Old Mobiles
iPhone guide: Cheap iPhones